What does the cryptic crossword clue "Fool capsized horse in charge – what a sap! (3,6)" mean?

The definition is "Fool". The wordplay uses a reversal. GUM (synonym="GUM") + ARABIC (synonym="ARABIC") = GUMARABIC The answer is GUMARABIC.

Fool capsized horse in charge – what a sap! (3,6)

Guardian Cryptic #29514 | 3 Down | 2024-10-15 flower